Rnon-soap synthetic-detergent



United States Patent rNON-SOAP SYNTHETIC DE'I-ERGENT? BAR AllenlH.Lewis, Berkeley, Calih, "assignor "to California Research CorporatiomsanFrancisco, can, a corpo- 'ra'tionofDelaware No Drawing. Applica'tionMayll, 1951, Serial N 0. 227,507

3 Claims. (CL 252-161) The invention t relates to a new and usefuldetergent composition. More particularly, it relates-to a "detergentcomposition which can the cast, "molded, or framed in conventionalmannerto-produce a detergent bar having superior properties.

*Inrecent years synthetic detergents, particularly thealkylzarylsulfonate detergents of "the type described in 'Lewis' U.S.'Patent No. 2,477,383, have won wide ac- "ceptance in householdapplications and-very large volumes of these materials are currentlymanufactured and sol'd. These synthetic detergents have been preparedfor the consumer in powdered or granular form andsubstantially all ofthese materials-have-been marketed-in that form. The desirability ofproducing a synthetic detergent bar has long been recognized andextensive experimental workdiasbeendirected tothis end as'evidenced, fornexample, by yMcCutcheons paper entitled .Synthetic Detergents r in BarvForm, Soap, December 1949, page 3-3ret: seq. Despite: intense "effort inthis .direction by a dargemumber of skilled research workers, nosatisfa'cto'ry tsynthetio detergenti-bar-has beenproduced whichhas metirvithwvide consumer" acceptance. The 1 principal. problem encounteredin an 'eftort to produce asynthetic; detergent bar is that of finding abinder which would hold the active detergent components together andgive the bar suitable physical characteristics. An acceptable bar shouldbe firm, cohesive, smooth and pleasant to the -touch,'lather and sudswell in hot and coldwatenand .be resistant to water in the sense that itdoes notbecome .soft and slimy in use or wastev away rapidly when wet,

'Tparaflin Waxand 70.to 30 parts by weightof an'organic sulfuricreact-ion'product type-detergent which is soluble in paratfin wax at atemperature inthe range 200 350 :F. can be cast,-mol'ded,'orframed toform a synthetic'detergent bar having'excellent physicaland de'tersiveprop- Thesecompositions are produced by melting paraflinwax-andhea'tingit to a ternperature in'therange 200 to 350" "F.,preferably 250'to 325 F., -and I stirring the organic 'ssulfuricreaction product type detergent into the J hot Lmolten waxto forma'clear, transparent liquid solu- ;tion, and cooling the ;-solutionuntil it solidifies.

-..In :a preferred embodiment of the invention, 1thede- .tergent.con3position .contains -40 -to 60 ;parts .by weight mt paraflinwax.andinaddition.to the 'wax .and organic sulfuric reaction producttype detergentasmall amount "ice not --exceeding about 10% "by weightbased on the total detergent composition of a polar organic hampo'u'rtd,

especially of a higher fatty-acid.

ln pro'ducing the'preferred composition, 1 the wax-is 5 melted'andheated to atem'peraturein therange about 250 to 325 F. as-indicatedabove; the higher fatty-acid is added to the hot 'molten' wax,and-the'organic'sulfuric reaction product type detergent is' then'dissolvedidthe hot mixture.

Three" important advantages attend 'the' use of anorganicpolar'eompoundin this manner. Fir'st; the organic sulfuric reaction product typedetergent dissolves "in the wax much more readily and much morerapidl'ywithconsiderably less agitation toprodnce'asolution of loweredviscosity; second, any tendency of 5 the organicsulfuricreaction-productto'drop out ofsolution'during cooling of the hot mixtureand'toa'gglomerate, 'formingapp'reciably large particles-of'detergentmaterial'in" the bars produced and thus to render themmacroscopicallyheterogeneous, is suppressed; and, third, the soliddetergent" bars produced are plasticized by thepolar material. I

The compositions of bothofthe'above embodiments derive theirprimaryvaluable.characteristicsffrom the wax and organic sulfuric reactionproducttype deter- 25 .gent components. Thepresence of thepolar-material considerably simplifiesthe process of makingthe detergentcompositions and enhances the already thoroughly acceptable propertiesof thejp'roduct. The compositions of both ofthe above embodiments-haveareasonable tolerance for the incorporation of inorganic builders which,although insoluble, maybe-dispersed in the .bar to improve theover-alldetersive action; operable ha'rs may contain up to, about. 25 byweight of. any: of .the usual inorganic builders such as alkali metalesulfates, alkali metal phosphates, alkali metal. polyphosphates andalkali metal silicates. -tlt-ispreferable, however, to.ke ep theinorganic salt content of the finished bar below about 12% of its totalweightin ordernto-avoid a tendency towardfrosting, -i. .-.e., theformation -ofinorganicfsalt 40 crystals on its surface.

.Thepreferred wax for use in compoundingathe compositions oftheri-nvention is. preferably -:a paraffin wax derived from";-,petroleumshaving a -melting ,-.point .above ..about .-125 -F. andhaviug arelatively. low oilcontent, desirably-below about 2% by-weight. The waremay-be either crystalline or amorphousand its melt-ing point may:rangeupto-about 175 F. Theordinaryede-oiledpetroieum waxes of commerceare entirely. satisfactory for compounding-the detergent compositions ofthei-nvention. .It should be understood that modificationsof thecharacteristics ot, paraffin -Wax by the incorporation -,-of smallamounts; of vegetable waxes -is -.not precluded.

, -As tindi'cated ahove, theactive detersive--component=-of thelcomposition is a water-soluble salt' of ana-organic'isul-:furioreaction producbwhichis soluble in paraflin-wax -at a -temperaturein the range -about- 200 350? F. =-These:prodnets are characterized byalarge. hydrophobic group con- -s-isti-ngsalmostentirely-of hydrocarbonmaterial and the smaller hydrophilic sulfuric acid residue. Themetal-co"mponent of a s-alt of the organist sulfuric reaction product isordinarily :sodiurn, but otheralkalimetals and: alkaline earthmetals,especially magnesium, may: beipresenttasdhe metallic component.-Materials ofithis general description have .the. common property-ofremaining highly dispersed in .thewvax matrix when thetcompositioniscoldgso th'at .the finished solid is characterized by macroscopic-zhomogeneity.

v.A very-considerable numberwof organic sulfuric-reaction .product type.-synthetic detergents .-aresdescni bedninnthe ,vliterature andvsever-al of -.these nmaterials tare? articleswof com-mercerproduced'incsubstantial -volume;.-tfor 'texample .alkyL-sulfates containing-1-0-.-to T20.carbon tatomsainathe alkyl group, alkyl sulfonatescontaining to carbon atoms in the alkyl group, sulfated monoglyceridesof coconut oil fatty acids and especially alkyl aryl sulfonatescontaining 10 to 20 carbon atoms in the alkyl side chain. While thesematerials have similar physical properties in that they are watersoluble and exhibit detersive and wetting properties and a structuralsimilarity in that they are all characterized by a large hydrophobicgroup consisting almost entirely of hydrocarbon material and a smallerhydrophilic sulfuric acid residue, they are not all suitable for use ascomponents of the compositions of this invention. To be useful here theorganic sulfuric reaction product type detergent must be soluble in hotparaffin wax.

. Some of these materials are soluble and some are not.

Without exception it has been found that those which are soluble in thewax remain highly dispersed in the wax matrix when the solution iscooled until the wax solidifies and that the solid is macroscopicallyhomogeneous. The solubility of any particular organic sulfuric reactionproduct type detergent, and hence its suitability for use in composingthe compositions of this invention, is readily determined by meltingparaffin wax, heating it to about 300 F. and stirring the detergent intothe wax. Suitable detergents dissolve in the wax forming a cleartransparent liquid solution at concentrations above 30% by weight.

Organic sulfuric reaction product type detergents having a branchedalkyl group containing 10 to 20 carbon atoms, especially the alkyl arylsulfonates described in Lewis Patent 2,477,383, are highly soluble inparaffin wax. The Lewis detergent is prepared by polymerizing propylene,separating a polypropylene fraction boiling from about 325 to 520 F.,alkylating a mononuclear aromatic hydrocarbon such as benzene, tolueneor xylene with the polypropylene, sulfonating the alkyl aromatichydrocarbon product and neutralizing the resultant sulfonic acid with analkali metal hydroxide or with an alkaline earth metal hydroxide.

The organic polar material which is desirably incorporated in thepreferred composition of the invention is preferably a higher fattyacid, i. e., aliphatic monocarboxylic acid containing 10 to 20 carbonatoms, for example stearic acid, oleic acid, palmitic acid and lauricacid.

As indicated above, the wax-synthetic detergent compositions of theinvention will tolerate the addition of fairly substantial amounts ofinorganic builders without too much sacrifice of their desirablebar-form properties. For example, the alkali metal carbonates,phosphates, borates, and silicates which are generally known as alkalinebuilders can be tolerated up to a maximum amount of about by weight ofthe total bar. Neutral builders such as sodium sulfate and sodiumchloride can be tolerated in similar amounts. Those skilled in the artwill recognize that perfume, coloring matter and fillers such asinfusorial earth and bentonite and. the allied group of clays may beincorporated in the finished bar. It must be recognized that theincorporation of insoluble material will proportionately increase theviscosity of the molten mix during the preparation of the product. Theterm consisting essentially employed in the appended claims is used inthe sense that conventional fillers, builders, perfumes, etc., may beadded to the waxdetergent compositions.

To prepare the compositions of the following examples paraffin wax wasmelted and heated to a temperature in the range about 250 to 325 F., andpreferably in the range 275 to 300 F., and the synthetic detergent wasstirred into the wax to dissolve it. At temperatures below 200 F. therate of solution and solubility of the detergent in the wax are low andthe detergent-wax mixtures prepared at such temperatures tend to bemacroscopically heterogeneous when cooled. At temperatures much above300 F. the synthetic detergent tends to char, and color of the ultimateproduct is poor. The temperature preferably should not exceed 325 F.When only wax and the synthetic detergent were employed in making thedetergent composition, extensive agitation and the application ofshearing force to the mixture was required to achieve homogeneity of theproduct. The addition of a higher fatty acid to the molten wax prior tothe addition of the synthetic detergent greatly facilitated thedissolving of the detergent and brought about a marked reduction in theviscosity of the solution. After the detergent is dissolved in the waxthe molten mixture may be poured into individual bar molds, or pouredinto a conventional frame and cooled until the mass solidifies, afterwhich the mass is cut into bars. Alternatively, the mass may be cooledto a temeprature just below its solidification point and then extrudedor pressed into bars.

Example I 70 parts by weight of de-oiled paraffin wax having a meltingpoint of 125 F. and an oil content below 2% by weight were heated to 310F. 30 parts by weight of a sodium alkyl benzene sulfonate containing 12to 15 carbon atoms in the alkyl chain were dissolved in the wax.Solution was accomplished by stirring the mixture for about 6 minutes.The fluidity of the solution was approximately that of hot molten wax.The solution was poured into a metal bar mold and cooled to roomtemperature. The bar separated from the mold without adhering to themetal. The bar was a light buff color and was similar to wax inconsistency. The bar was smooth and pleasant to the touch, was perfectlyhomogeneous to visual inspection, and floated in water. When the bar wasworked with the hands in the usual manner with hot or cold water, itlathered, but rather poorly.

Example 2 60 parts by weight of the paraflin wax of Example 1 wereheated to 300 F. 40 parts by weight of sodium polypropylene benzenesulfonate containing 12 to 15 carbon atoms in the polypropylene radicalswere dissolved in the molten wax. The wax was cast in bar form as inExample 1. The lathering properties of this bar were considerably betterthan those of the bar in Example 1. The specific gravity of this bar wasslightly less than 1.

Example 3 47.5 parts by weight of the paraffin wax of Example 1 weremelted and heated to 300 F. 52.5 parts by weight of a mixture of sodiumpolypropylene benzene sulfonate containing 12 to 15 carbon atoms in thepolypropylene groups and sodium sulfate were incorporated in the moltenwax. The ratio of sulfonate to sulfate in the solute was 60:40. Theliquid dispersion produced had a considerably higher viscosity than thesolutions of Examples 1 and 2 due to the salt content. The mixture wasbarely pourable at 300 F. The mixture was cast in bar form as inExample 1. The bar lathered well in hot and cold water, but frostedslightly after wetting because of the sodium sulfate content.

Example 4 47.6 parts by weight of the wax of Example 1 were melted andheated to about 300 F. 9.6 parts by weight of palmitic acid weredissolved in the molten wax and then 42.8 parts by weight of a mixtureof sodium polypropylene benzene sulfonate containing 12 to 15 carbonatoms in the polypropylene radicals and sodium sulfate were incorporatedin the wax-acid solution. The ratio of sulfonate to sulfate in thelatter solute was :10. The resulting dispersion was highly fluid and theapparent rate of solution of the sulfonate in the wax was rapid, thesulfonate apparently dissolving completely after 2 minutes of stirring.The resulting mixture was cast in bar form. The bar lathered well, butthe foam broke more rapidly than the foams produced by the bars inExamples 1 to 3 inclusive, presumably because of the high fatty acidcontent of the bar.

Example 5 52.4 parts by weight of the parafiin wax of Example 1 weremelted and heated to about 300 F. 4.8 parts by weight of palmitic acidwere dissolved in the molten wax and then 42.8 parts by weight of thesulfonate-sulfate mixture of Example 4 were incorporated in the wax-acidsolution. The resultant mixture was cast in bar form. The resultant barlathered well and the foam was more stable than the foam produced by thebar of Example 4, but not quite as stable as the foam produced by thebar of Example 2.

Example 6 56.2 parts by weight of the paraifin wax of Example 1 weremelted and heated to about 300 F. One part by weight of palmitic acidwas dissolved in the molten wax and then 42.8 parts by weight of thesulfonate-sulfate mixture of Example 4 were incorporated in the wax-acidsolution. The presence of the palmitic acid in this small amountnoticeably increased the apparent rate of solution of the sulfonate andlowered the viscosity of the resulting mixture. The final mixture wascast in bar form. The bar lathered well in both hot and cold water andthe foam produced was apparently identical with the foam produced by thebar of Example 2 with respect to stability.

Example 7 52.3 parts by weight of the wax of Example 1 were melted andheated to about 300 F. 1.8 parts by weight of palmitic acid weredissolved in the molten wax and then 40.6 parts by weight of thesulfonate-sulfate mixture of Example 4 were incorporated in thesolution. 5.3 parts by weight of glycerine were incorporated in theresultant mixture. The final mixture was cast in bar form. This bar wassimilar in all of its properties to the bar produced in Example 6.

Example 8 57.7 parts by weight of a de-oiled paraflin wax having amelting point of 143 F. were melted and heated to about 300 F. 42.3parts by weight of the sulfonatesulfate mixture of Example 4 wereincorporated in the molten wax. The mixture was cast in bar form. Thebar lathered well in both hot and cold water.

Example 9 35 parts by weight of the paraflin wax of Example 1 weremelted and heated to about 300 F. 5 parts by weight of palmitic acidwere dissolved in the molten wax and then 60 parts by weight of thesulfonate-sulfate mixture of Example 4 were incorporated in thesolution. The final mixture was cast in bar form. This bar had excellentlathering properties, and was apparently equal in this respect to a goodgrade of toilet soap. During prolonged use, the bar wore away smoothlyand showed no tendency to soften or crumble when exposed to the usualconditions of household use.

Example 10 45 parts by weight of the paratfin wax of Example 1 weremelted and heated to about 300 F. 5 parts by weight of stearic acid weredissolved in the molten wax and then 50 parts by weight of an alkyl arylsulfonate prepared by alkylating benzene with a propylene polymerfraction boiling over the range about 360 to 520 F., sulfonating thealkylate, and neutralizing the resultant sulfonic acid with sodiumhydroxide, were dissolved in the wax-acid mixture. The resultantsolution was cast in bar form. This bar had excellent latheringproperties and was durable in ordinary household use.

The bars prepared in all of the foregoing examples were macroscopicallyhomogeneous as they left the mold and all of them retained theirhomogeneous appearance throughout prolonged use, with the exception ofthe bar produced in Example 3 which showed a tendency to frost. Thematerials of which each of the exemplified bars are formed do not appearto wet the surfaces of metallic molds and are readily freed from themold when cooled. The exemplified bars may be remelted and recastwithout loss of homogeneity and apparently without change in any of thephysical or chemical properties of the composition.

I claim:

1. A firm, cohesive and macroscopically homogeneous detergent barconsisting essentially of 40 to 60 parts by weight of parafiin wax, 2 to5 parts by weight of a fatty acid containing 10 to 20 carbon atoms permolecule and 60 to 40 parts by weight of a mixture of water-solublealkyl aryl sulfonates, the alkyl groups being propylene polymerscontaining predominantly from 12 to 15 carbon atoms.

2. A firm, cohesive, macroscopically homogeneous detergent barconsisting essentially of 40 to 60 parts by weight of paraffin wax, 60to 40 parts by weight of an alkyl benzene sulfonate detergent having 10to 20 carbon atoms in its alkyl group, 1 to 10 parts by weight of afatty acid containing 10 to 20 carbon atoms per molecule, and from 1 to25 parts by weight of a water-soluble inorganic builder.

3. A process for producing a macroscopically homogeneous detergent barwhich comprises forming a mixture of molten paraffin wax and a higherfatty acid, heating the mixture to a temperature in the range 250 to 325F., dissolving an alkyl benzene sulfonate detergent having 10 to 20carbon atoms in its alkyl group in the hot mixture and cooling thesolution to form a macroscopically homogeneous solid, the proportions ofthe components in the solution being 40 to 60 parts by weight of wax, 1to 10 parts by weight of a fatty acid containing 10 to 20 carbon atomsper molecule and 60 to 40 parts by weight of sulfonate.

References Cited in the file of this patent UNITED STATES PATENTS2,175,285 Duncan Oct. 10, 1939 2,356,903 Wood Aug. 29, 1944 2,462,758Malkemus Feb. 22, 1949 2,653,913 Van Dijck Sept. 29, 1953 2,678,921Turck May 18, 1954 FOREIGN PATENTS 583,028 Great Britain Dec. 5, 1946592,206 Great Britain Sept. 10, 1947

1. A FIRM, COHESIVE AND MACROSCOPICALLY HOMOGENEOUS DETERGENT BARCONSISTING ESSENTIALLY OF 40 TO 60 PARTS BY WEIGHT OF PARAFFIN WAX, 2 TO5 PARTS BY WEIGHT OF A FATTY ACID CONTAINING 10 TO 20 CARBON ATOMS PERMOLECULE AND 60 TO 40 PARTS BY WEIGHT OF A MIXTURE OF WATER-SOLUBLEALKYL ARYL SULFONATES, THE ALKYL GROUPS BEING PROPYLENE POLYMERSCONTAINING PREDOMINANTLY FROM 12 TO 15 CARBON ATOMS.